Humidifier and heater for delicered gases

ABSTRACT

A humidifier to moisten and heat delivered gases from a source such as a respiratory machine. In a preferred form, the humidifier is a disposable assembly unit formed from a thermoplastic material in which the heating means is part of the assembly unit, removable or fixed. The structure of the humidifier further provides an improved handling of the delivered gas for moistening and heating in that gas is delivered through an inlet and tube means to a rebound chamber in a lower portion of the container where the gas is moved upwardly through a dispersion plate for bubbling through a body of water prior to discharge through an outlet.

Umted States Patent [1 1 [111 3,757,082 Goicoechea Sept. 4, 1973HUMIDIFIER AND HEATER FOR 2,405,494 8/l946 Dupuy 55 255 x DELIVEREDGASES 3,294,380 12/1966 Born 261/121 R Inventor: George LeandroGoicoechea,

Chicago, 111.

Critical Care Systems, Inc., Village, lll.

Filed: Jan. 21, 1972 Appl. No.: 219,697

Assignee:

References Cited UNITED STATES PATENTS 6/1970 Jaffee et a1. 261/2411/1966 Walker, Jr.. 219/271 X Primary Examiner-C. L. AlbrittonAttorney-Dominik, Knechtel & Godula [57] ABSTRACT A humidifier tomoisten and heat delivered gases from a source such as a respiratorymachine. In a preferred form, the humidifier is a disposable assemblyunit formed from a thermoplastic material in which the heating means ispart of the assembly unit, removable or fixed. The structure of thehumidifier further provides an improved handling of the delivered gasfor moistening and heating in that gas is delivered through an inlet andtube means to a rebound chamber in a lower portion of the containerwhere the gas is moved upwardly through a dispersion plate for bubblingthrough a body of water prior to discharge through an outlet.

17 Claims, 8 Drawing Figures PATENTED SEP 4191s SHEET 1 BF 2 FIG.|

FIG. 2

FIG. 3

FIG. 7

HUMIDIFIER AND HEATER FOR DELIVERED GASES This invention relates to animproved humidifier for delivered gases, such as from a respiratorymachine. The invention particularly relates to a humidifier which can beproduced at a low cost per unit so that it may be disposable, eventhough means are provided for electrically heating the water in thecontainer to predetermined temperatures.

, It is recognized that a humidifier is essential for moisteningdelivered gases such as oxygen or a mixture of air and oxygen from arespiratory machine prior to inhalation by a subject. It has also becomethe accepted practice to heat the humidifier so that the water thereinreaches temperature levels which are closer to that of body temperature.The subject therefore inhales gas and water vapor which is warmed sothere is no serious challenge to respiratory tissues during inhalation.Such humidifiers can be prefilled, or can be filled with water whenbeing prepared for connection to the respiratory machine and used by thesubject. Sterility of the water is not an important criterium becausemicroorganisms are not carried by gases for all practical purposes. Theexpense of the original humidifier is a consideration, as well as thetime and expense involved in disassembling a unit for cleaning, removingmineral formations from heating elements, and the like.

It is accordingly one important object to provide an improved humidifierfor delivering gases in which electrical heating elements are made apart of the unit assembly, but separated from the container portion inwhich water is placed. It is a particular advantage to attain such aunit assembly at very low cost per unit assembly by forming the assemblyfrom thermoplastic material, thereby permitting disposal of the unitwith out seriously adverse economies.

It is yet another important object of the present invention to providean improved humidifier for moistening and heating delivered gaseswhereby such gases are moved in an improved way through a delivery tubeinto a rebound chamber in the container wherein said gas is dispersed byrebounding from the floor portion, or otherwise, followed by upward flowthrough a dispersion plate which assures widely distributed contact witha body of heated water above the plate prior to discharge for deliveryto a subject.

A still yet another important object of the invention is the improvedhumidifier and heater in which a heating housing is secured in differentways to a water container, said heating housing havingeconomicallymanufactured heating elements sensed by a temperature probeand controlled by a thermostat separate from the unit assembly.

A still further object of the present invention is to provide animproved humidifier and heater having four components, each of which iseconomically molded from plastics, such components being a removable capwith gas inlets and outlet; a dispersion plate and gas conveying tubemeans; a water container; and a heating housing with heating elementsand electrical connector; and all of the foregoing components forming aunit assembly which can be disposed after use without economic burden.

Still yet another object of the present invention is to provide animproved humidifier and heater unit assembly with improved means fordirecting a delivered gas through a body of water inside a container tothe bottom of a container wherein such gas is rebounded or otherwisedispersed upwardly so that widely distributed gas particles aredesirably moistened in a body of water which is further heated todesired temperature levels, all of said desired features beingaccomplished by thermoplastic parts, one of said parts additionallyhaving electric heating elements and means associated therewith.

These and still other objects are now attained by the present inventionwhich is shown in the following disclosure, including drawings wherein:

FIG. 1 is a somewhat schematic side elevational view showing thehumidifier and heater as part of a connected line between a gas sourceand a receiving station;

FIG. 2 is a side elevational view in section on an enlarged scale, ofthe humidifier and heater;

FIG. 3 is a schematic view, on a reduced scale, of the electric circuitsfor the heater provided in the unit assembly;

FIG. 4 is a plan view partly in section and with parts removed, of theheating housing, on a scale similar to that of FIG. 2;

FIG. 5 is a plan view of the gas dispersion member which is a componentin the unit assembly;

FIG. 6 is a portional side elevational view showing the heating housingand electrical connector in the humidifier;

FIG. 7 is a view similar to that of FIG. 6 but representing analternative embodiment wherein the container is removably mounted on aheater housing, and

FIG. 8 is a side elevational view of an alternative embodiment showing awater reservoir mounted on a humidifier provided with heat dissipating.

Referring now to the drawings, the view of FIG. 1 schematicallyindicates a gas supply 10 such as a respiratory machine. An oxygenmixture is delivered along a line 12 to a humidifier and heater showngenerally as 14. Moistened and heated gas moves out'of the humidifierand heater through a line 16 to a human subject 18, or to a receivingstation prior to ultimate delivery to a subject. The humidifier andheater 14 is provided with heating means to which is connected femaleplug 20 having a temperature probe 22. An electric cord 24 joins plug 20to a thermostat control 26, and a male plug 28 is provided forconnection to a 110 volt alternating current source. The thermostatcontrol 26 presets a small range of moderate temperature levels, say F.,F., 98 F. and F.

Considering the humidifier and heater in detail, there is provided aremovable top cap 29 which is formed with a continuous inclined sidewall30 and a flat, top portion 31. The cap is integrally formed with a gasoutlet 32 having a stepped annular sidewall 33; and with a gas inlet 34having a similar stepped sidewall 35. The

center axis of the passageways of the outlets is disposed" tending tube36 which forms a continuous passageway with inlet 34, such passagewaybeing coaxial with respect to the inlet and downwardly extending tube.The cap is provided with a continuous bead 38 at its lower edge, and acontinuous groove 39 is formed within the bead.

The removable cap is shown mounted on a container shown generally as 40,and the body of water is within such container its level being indicatedat 42. The downwardly extending tube 36 is provided with a oneway flapvalve 43 at its ends, and such flap valve is designed to prevent watervapor and condensation from entering a line leading to the gas supply10.

The container has a continuous sidewall 44. The illustrated embodimentshows the continuous sidewalls as being four sided in a somewhatrectangular pattern, but it should be understood that the continuoussidewalls may be another configuration, including curvilinear. Thehumidifier and heater, illustrated as having four sidewalls, is providedwith shoulders or flats 46 on the inside of each of its sidewalls, twoof such flats being shown in the view of FIG. 2. Such flats arepositioned substantially closer to the floor portion 67 of the containerthan to the top edge of the container which is seated in groove 39 ofbead 38. The bottom edge of the continuous sidewall 44 is shown as acontinuous skirt portion 48 to serve a purpose which will be laterdescribed.

An integrally formed gas dispersion member shown generally as 49 isseated on the flats 46. Such a gas dispersion member has an upwardlyextending gas conveying tube 50 having a diameter slightly oversizedrelative to the diameter of downwardly extending tube 36 to allow atelescoping connection, as shown. The tube 50 extends upwardly from asubstantially planar gas dispersion plate 52 having a plurality of gastransmitting holes such as 54. In the illustrated embodiment the plate52 is four sided with holes 54 randomly distributed over substantiallyits entire planar area. When the gas dispersion member is seated on theshoulders, a gas rebound chamber 55 is defined between such dispersionplate 52 and the floor portion 47 of the container. The rebound chamberforms a minor volume of the container marked by the continuous top edgeof the continuous sidewall 44.

The delivered gas moves through inlet 34, downwardly extending tube 36,upwardly extending tube 50, and through the water present therein. Suchgas is then dispersed in rebound chamber where at least some of the gasis rebounded from the floor portion 47through the holes 54 anddispersion plate 52. When reference is made to rebound chamber orrebounding gas, it should be understood that such term generally refersto the gas below the dispersion plate and its'eventual upward movementthrough the dispersion plate. Some or all of the gas may actually notrebound from the floor portion, although it is preferred to deliver thegas at pressure levels which are expected to cause such rebound from thefloor portion.

An electrical heating chamber or heating housing shown generally'at 56is mounted relative to floor portion 47 of the container. The heatinghousing is formed with a bottom portion 57 and a continuous sidewallportion 58. The heating chamber is substantially filled with insulatingmaterial 59 which may be in the form of a pad made of fiberglass. Thefibrous material is preferably packed to a density of about threepounds, and such fibrous material is also preferably held in place by aplurality of integrally formed buttons 60 mounted on the bottom portion57 inside the heating housing or chamber. The continuous sidewall 58 ofthe heating housing is shown provided with a continuous flange support6K to form a supporting overlapping joint between skirt portion 48 andupper portions of the sidewalls 58. The overlapping relationship betweenthe skirt portion and upper portions of the sidewalls 58 of the heatinghousing allow the heating housing to be securely fitted to the bottom ofthe container. This may be a close frictional fit to allow removal ofthe heating housing for subsequent use, or such heating housing may bedisposed with the container, cap and dispersion member of the unitassembly. If desired, the heating housing may be bonded to the skirtportion by bonding material, sonic bonding, or by other means.

The heating means provided in the heating housing include a male plugshown generally as 62, one of the Ark-Less pin connectors being shown at63. Plug blocks 64 support the pin connectors, such blocks being mountedto inset portion 65 of continuous sidewalls 58. A temperature sensorpassageway 66 is provided in the inset wall portions 65 of the plugassembly. Conductors 67 join the pin connectors to electroheatingelements 68. Another conductor 69 completes the circuit between theheating elements 68.

The female plug, previously identified generally as 20, is shown with atapered plug body 72 and pin sockets 74. The previously identifiedtemperature probe 22 extends from the plug body 72. The foregoingelectrical connections may be further understood by considering theschematic electrical circuit of FIG. 3. The schematic circuit showsathermostat 26 as further having a dial set for presetting thetemperature. A conventional conductor current cut off 82 is madeoperational when the predetermined temperature level is reached. Circuitbreakers may also be conventionally provided to become operational ifpredetermined temperature levels are exceeded. As a representativeembodiment, a temperature level of, say, 115 F. will still result intemperatures of the delivered moistened gases below about 87 F whenusing a 48 inch delivery tube from gas outlet to subject.

The view of FIG. 7 is intended to represent an alternative embodiment inwhich a water container 84 has a bottom shoulder 86 formed by insetbottom portion 88 if the container. The shoulder 86 and inset portion 88form a complementary seat with sidewall 88 of a reusable heatinghousing. The water container forms a loose frictional fit on the heatingchamber so that it may easily be mounted and removed so that asubsequent water container may be placed on the reusable heatingchamber. The insulating material 90 again substantially fills theheating chamber between the continuous sidewall 88, the floor portion 92and the heating elements, one of which is shown at 94. Buttons 96 areagain shown to help anchor the pad of insulating material 90.

The humidifier and ventilator may be delivered to a user, such ashospital personnel, in a form substantially as shown in'FlG. 2. The cap29 may be easily removed and the container may be filled with watersubstantially to the top edge of the sidewall 44 of the container. Thecap is remounted by telescoping downwardly extending tube 36 to upwardlyextending tube 50. A line 12 is connected to the gas inlet 34 from therespiratory machine, and the line 16 is connected to the outlet and tothe intake device used by the subject. The heating elements 68 in theheating chamber are positioned adjacent to the floor portion 47 of thecontainer, and the thermostat is preset at the desired temperaturefollowing connection of plug 20 to plug 62 of the heating housing. Theinsulating material will direct substantially all of the heat towardsthe floor portion 47 of the container to desirably heat the body ofwater therein. If desired, a communicating vent 98 may be provided inthe stepped annular wall 35 of the inlet so that inhalation by thesubject will trigger delivery of gas into the inlet. The delivered gaswill be emptied into the rebound chamber 55 and will have to bedistributed generally throughout the major portion of the body of waterlocated above the dispersion plate 52. Following desired use by thesubject, the water may be emptied from the container and the entirehumidifier and heater unit assembly may be disposed. On the other hand,the heater housing may be retained by removing the container anddisposing only of said container, gas dispersion member and removablecap. In the preferred form, the heating chamber is an open top housingso that the heating element such as 68 may directly adjoin or even abutthe bottom or floor portion 47 of the container. The heating housing maybe used in conjunction with thermoplastic containers becausethermoplastic materials are readily available which are stable attemperature levels of at least about 100 F. In the preferred practice,the body of water within the container will not be heated above about105 F. since higher temperatures are not desirable for inhalationtherapy.

FIG. 8 shows an alternative embodiment wherein a cap 100 is providedwith fittings 102, 104 for receiving communicating tubes of an assemblyto maintain desired water levels within the container 106. The mountings102, 104 are in the form of bosses having passageways therein to receiveclosely fitting tubes 108, 110.

The water and pressure responsive tubes pass through a closure 112 ofwater reservoir bottle 114. Such a bottle may have volume markings 116to measure the lowering of the water level 118 of the body of waterwithin such a bottle. The bottle is supported in the inverted verticalposition by band 120 which is mounted in the usual way to stand, abracket arm 122 whereof is only shown.

When the water level 124 in the container 106 falls below the bottom ofpressure responsive tube 112, pressure changes in reservoir bottle 114will cause the water level 118 to drop, and thereby move water throughwater tube 108 into container 106. Such water movement will continueuntil water level 124 again closes the bottom of pressure responsivetube 112. This embodiment shows a plurality of heat dissipating fins 126extending peripherally along the bottom of container 106. Such fins maybe provided out of materials which are more quickly heat conductive,they may even be plastic. In any event, the fins facilitate the heatdissipation from any undue buildup of heat in the container. Such finsare shown extending to the bottom of the container 106, short of heatinghousing 128.

The embodiments shown herein are preferably used by nomagrams so thatthe practitioner can ascertain desired relative humidity of thedelivered gases for a given flow rate of gas through the inlet relativeto prescribed temperatures.

The claims of the invention are now presented in terms which may beadditionally understood by considering the foregoing disclosure.

What is claimed is:

1. A humidifier for delivered gases including a water container having acontinuous sidewall, a top,

and a bottom,

an inlet for delivered gas on said container,

an outlet for moistened and heated gas on said container electricheating means mounted to the bottom of the container, including heatingelements and a temperature sensor, to warm water placed in the containerto preset temperature levels,

a gas dispersion plate mounted within said container closer to thebottom than to the top to define a gas rebound chamber therebelow, and

tube means for conveying delivered gas below the dispersion plate intosaid rebound chamber, whereby gas moves upwardly through the dispersionplate through water placed in the container and out of said gas outlet.

2. The humidifier for delivered gases which includes the features ofclaim 1 above, wherein the heating elements of said means are within aheating housing mounted to the bottom of said container, said heatinghousing further including conducters and a connector plug, said plughaving a passageway to receive a temperature probe.

3. A humidifier for delivered gases which includes the features of claim2 above wherein said heating elements are positioned adjacent the bottomof the container, and which further includes insulation material tosubstantially fill the heating housing so that heat from said heatingelement is directed substantially towards the bottom of said container.

4. A humidifier for delivered gases which includes the features of claim3 above, wherein said heating housing has a continuous sidewall, a floorportion and an open top wherein said heating elements are positionedadjacent the bottom of the container, and wherein said insulatingmaterial is positioned between the sidewall, floor and the heatingelements.

5. A humidifier for delivered gases which includes the features of claim4 above, wherein said insulating material is fibrous material, and whichfurther includes a plurality of fixed buttons on the floor of theheating housing inside the heating housing to hold the fibrous material.

6. A humidifier for delivered gases which includes the features of claim4 above wherein said heating housing is removably secured to the bottomof said container.

7. A humidifier for delivered gases which includes the features of claim6 above wherein said heating housing is removably secured to the bottomof said container by overlapping respective sidewall portions of saidcontainer and said heating housing.

8. A humidifier for delivered gases which includes the features of claim4 above wherein said heating housing is secured through the bottom ofsaid container, whereby the container and the heating housing may beused and diposed as a unit.

9. A humidifier for delivered gases which includes the features of claim8 above, wherein the container, the dispersion plate, the tube means,and the heating housing are formed of thermoplastic material which isstable up to at least about F.

10. A humidifier for delivered gases-which includes the features ofclaim 1 above, wherein said container top is a removable cap, andwherein said gas inlet and outlet are formed on a top, flat portion ofsaid cap.

11. A humidifier for delivered gases which includes the features ofclaim 10 above wherein said dispersion plate includes an integrallyformed and upwardly extending tube, wherein said top cap includes adownwardly extending tube having a passageway coaxial with the gas inletpassageway, and wherein the downwardly extending tube is telescopedwithin said upwardly extending tube to form a passageway in the gasinlet, the downwardly extending and upwardly extending tubes.

12. A humidifier for delivered gases which includes the features ofclaim 11 above wherein said dispersion plate and integral upwardlyextending tube are removably seated on integrally formed flaps extendingupwardly from the continuous sidewall of the container.

13. A humidifier for delivered gases which includes 7 tegrally formedupwardly extending tube, container sidewalls, and heating housing isformed of thermoplastic material which is stable at temperatures of atleast about F.

15. A humidifier for delivered gases which includes the features ofclaim 14 above wherein the inlet and outlet extend normally to the top,flat portion of the cap, and wherein said inlet and outlet are formed byannular stepped walls to provide an anchoring grip for flexible,resilient tubing.

16. A humidifier for delivered gases which includes the features ofclaim 15 wherein the annular, stepped wall of the gas inlet has anaperture communicating the passageway of the inlet with ambient air toaid delivery of a gas for a source such as a respiratory unit.

17. A humidifier for delivered gases which includes the features ofclaim 1, which further includes means to maintain constant water levelwithin the container, such means including a water reservoir, a watertube connecting a body of water in the reservoir with the body of waterin the container, and a pressure responsive tube connecting a pressuredhead in the reservoir to the pressure head in the container, wherebylowering of the water level in thecontainer induces movement of waterfrom the reservoir to maintain the water level in the containersubstantially constant.

1. A humidifier for delivered gases including a water container having acontinuous sidewall, a top, and a bottom, an inlet for delivered gas onsaid container, an outlet for moistened and heated gas on said containerelectric heating means mounted to the bottom of the container, includingheating elements and a temperature sensor, to warm water placed in thecontainer to preset temperature levels, a gas dispersion plate mountedwithin said container closer to the bottom than to the top to define agas rebound chamber therebelow, and tube means for conveying deliveredgas below the dispersion plate into said rebound chamber, whereby gasmoves upwardly through the dispersion plate through water placed in thecontainer and out of said gas outlet.
 2. The humidifier for deliveredgases which includes the features of claim 1 above, wherein the heatingelements of said means are within a heating housing mounted to thebottom of said container, said heating housing further includingconducters and a connector plug, said plug having a passageway toreceive a temperature probe.
 3. A humidifier for delivered gases whichincludes the features of claim 2 above wherein said heating elements arepositioned adjacent the bottom of the container, and which furtherincludes insulation material to substantially fill the heating housingso that heat from said heating element is directed substantially towardsthe bottom of said container.
 4. A humidifier for delivered gases whichincludes tHe features of claim 3 above, wherein said heating housing hasa continuous sidewall, a floor portion and an open top wherein saidheating elements are positioned adjacent the bottom of the container,and wherein said insulating material is positioned between the sidewall,floor and the heating elements.
 5. A humidifier for delivered gaseswhich includes the features of claim 4 above, wherein said insulatingmaterial is fibrous material, and which further includes a plurality offixed buttons on the floor of the heating housing inside the heatinghousing to hold the fibrous material.
 6. A humidifier for deliveredgases which includes the features of claim 4 above wherein said heatinghousing is removably secured to the bottom of said container.
 7. Ahumidifier for delivered gases which includes the features of claim 6above wherein said heating housing is removably secured to the bottom ofsaid container by overlapping respective sidewall portions of saidcontainer and said heating housing.
 8. A humidifier for delivered gaseswhich includes the features of claim 4 above wherein said heatinghousing is secured through the bottom of said container, whereby thecontainer and the heating housing may be used and diposed as a unit. 9.A humidifier for delivered gases which includes the features of claim 8above, wherein the container, the dispersion plate, the tube means, andthe heating housing are formed of thermoplastic material which is stableup to at least about 100* F.
 10. A humidifier for delivered gases whichincludes the features of claim 1 above, wherein said container top is aremovable cap, and wherein said gas inlet and outlet are formed on atop, flat portion of said cap.
 11. A humidifier for delivered gaseswhich includes the features of claim 10 above wherein said dispersionplate includes an integrally formed and upwardly extending tube, whereinsaid top cap includes a downwardly extending tube having a passagewaycoaxial with the gas inlet passageway, and wherein the downwardlyextending tube is telescoped within said upwardly extending tube to forma passageway in the gas inlet, the downwardly extending and upwardlyextending tubes.
 12. A humidifier for delivered gases which includes thefeatures of claim 11 above wherein said dispersion plate and integralupwardly extending tube are removably seated on integrally formed flapsextending upwardly from the continuous sidewall of the container.
 13. Ahumidifier for delivered gases which includes the features of claim 12above wherein the downwardly extending tube is fitted with a one-wayvalve above the water level mark in the container to block entry ofwater vapor into a conduit mounted to the gas inlet tube.
 14. Ahumidifier for delivered gases which includes the features of claim 11above wherein the entire assembly of caps with integrally formed inlet,outlet and downwardly extending tubes; dispersion plate with integrallyformed upwardly extending tube, container sidewalls, and heating housingis formed of thermoplastic material which is stable at temperatures ofat least about 100* F.
 15. A humidifier for delivered gases whichincludes the features of claim 14 above wherein the inlet and outletextend normally to the top, flat portion of the cap, and wherein saidinlet and outlet are formed by annular stepped walls to provide ananchoring grip for flexible, resilient tubing.
 16. A humidifier fordelivered gases which includes the features of claim 15 wherein theannular, stepped wall of the gas inlet has an aperture communicating thepassageway of the inlet with ambient air to aid delivery of a gas for asource such as a respiratory unit.
 17. A humidifier for delivered gaseswhich includes the features of claim 1, which further includes means tomaintain constant water level within the container, such means includinga water reservoir, a water tube connecting a body of water in thereservoir with the body of water in the container, and a pressureResponsive tube connecting a pressured head in the reservoir to thepressure head in the container, whereby lowering of the water level inthe container induces movement of water from the reservoir to maintainthe water level in the container substantially constant.